As a method for producing an optically active substance at the position 5 of a (4,5-dihydroisoxazol-3-yl)aryl compound, each of methods described in Patent Document 1 and Non Patent Document 1 has been known.
As a method for producing an optically active substance at the position 5 of a 4-(4,5-dihydroisoxazol-3-yl)benzoic acid compound, a production method according to a diastereomeric salt method has been known (see, for example, Patent Document 2).
As a method for producing an optically active substance at the position 5 of a 4-(4,5-dihydroisoxazol-3-yl)-N-thietan-3-yl-benzamide compound or a related compound, a method described in Patent Document 3 has been known.
As a general method, a method for preparing an optically active substance from a (4,5-dihydroisoxazol-3-yl)aryl compound that is a racemate has also been known, and in the method, optical resolution is conducted by using a column supporting an optically active carrier.